SINGAPORE – Typically one of Singapore’s drier months, March 2025 broke records as being the country’s wettest March due to an unusual monsoon surge.
March 19 to 20
, “contributed significantly” to that month’s rainfall, said the Meteorological Service Singapore (MSS) on Jan 8.
In its annual climate and weather report for 2025, MSS noted that the islandwide average rainfall over the two days was 272.3mm. This exceeded the month’s long-term average of 209.7mm.
The average rainfall in March 2025 was 130 per cent above the norm, at 482.9mm, added the weatherman.
Overall, 2025 was off to an exceptionally wet start due to a series of monsoon surges – a weather phenomenon that brings rain and cooler weather to the country – in January and March.
Downpours in both months due to three monsoon surge events made 2025 the seventh-wettest year for Singapore since 1980, said MSS.
Monsoon surges occur when bursts of cold, dry air from wintry regions like Central Asia move over the warm waters of the South China Sea, picking up moisture. This brings extensive rainfall, strong winds and cooler temperatures to Singapore.
At times, near Singapore, the winds may interact with a separate whirlpool of air, where winds are forced to move upwards, forming clouds. This is called a low-pressure vortex, which worsens the deluge over the country.
While it is common for such surges to occur in December and January during the wet phase of the north-east monsoon, the March surge was unusual as it happened during the dry phase of the monsoon season.
The dry phase of the monsoon season is called such as the rain band shifts away from Singapore.
Asked about possible reasons for the unusual monsoon surge event then, an MSS spokesperson told The Straits Times that the rain band had remained close to Singapore last March.
“At the same time, other key features of a strong monsoon surge were present, (including) the presence of a vortex near Singapore,” added the spokesperson.
